Roll out the red carpet for the baddest Mustang ever. It's called "King of the Road," and it lives up to the moniker. Despite these challenging economic times, Ford hasn't been shy about offering up specialty Mustangs, and that's mighty fortunate for enthusiasts. This trend has been going on since the early-'90s, and you've been eating them up.
Ford fanatics can include the '93 Cobra, all three R-model Mustangs, the supercharged Lightning, the beloved Terminator, the Ford GT supercar, and more recently, the Shelby GT500 in their dream garage. Additional models consist of the '01 and '08 Bullitts and the Mach 1, too. But with the bar being raised so high, one can only wonder, what's next?
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You're Looking at the most powerful Mustang engine ever to come from Ford. It's rated at 540 hp and 510 lb-ft. We observed 511 hp at the wheels on JDM Engineering's Dynojet chassis dynamometer. Horsepower was still climbing when the engine hit redline (6,250 rpm), so there's likely to be plenty more power in there. | 
The KR wears a set of forged and polished 18x9.5-inch aluminum wheels wrapped in unique Goodyear F1 rubber. |
Ford answered quickly on the heels of the 500-horse GT500 with the hotter 540hp Shelby GT500KR-the most powerful Mustang ever. It's also the most expensive, with a sticker of $79,995, and it's one of the most limited in production. This year, just 1,000 examples will be produced, with another 746 to be built in 2009, of which 571 will be available for U.S. customers.
The alliance between Ford, Ford Racing, SVT, and Shelby is strong, and the GT500KR is shaping up to be the most spectacular example in the Mustang's 45-year history. One could say the KR epitomizes Mustang performance, combining what Ford knows about style, supercharging, and real-world, on-track performance.
Along with the thundering supercharged V-8, the KR is enhanced with a spectacular carbon-fiber hood and front splitter, and an aero-friendly rear spoiler, all in the name of improved balance. The KR sits low, has forged wheels, sticky Goodyear tires, and functional brake-cooling ducts, to name a few things.
THE GT500KR performed flawlessly on the street, the strip, and at Miller Motorsport Park in Utah. This, the hottest Mustang ever, was well balanced and plenty powerful. | 
Interior Features include minor upgrades such as a Shelby dash plaque and a short-throw shifter with white ball knob. |  |
Drive One.
To find out how good the KR really is, MM&FF put a few examples through the ringer. Yes, we drove three or four different KRs on the streets, while tackling a road course and pounding the quarter-mile in this all-inclusive road and track test.
We traveled halfway across the country to Miller Motorsports Park in Tooele, Utah, where we exercised all 540 ponies and the 1.0g-capable suspension on the 2.2-mile West road course (there are multiple configurations at MMP). MMP is a world-class facility, which plays host to a Grand-Am series event as well as the Ford Racing High Performance Driving School. Before unleashing us in the KR, Ford executives allowed us to push hard in a standard GT500 (along with a few other Mustangs).
After getting settled, we cracked off the KR's ignition, and the 5.4 rumbled to life. At idle it cackles with authority, blip the pedal and it sounds oh-so good, like only a strong V-8 can deliver. Leaving pit lane, we whacked the throttle and were rewarded with an amazing song that never got old. The sweet symphony comes from a finely tuned H-style pipe, rather than the "X" that resides in the 500hp GT500. The KR also has less-restrictive baffles and 3.5-inch exhaust tips. The new exhaust also helps shed 20 pounds.
Other power enhancements include a cold-air package that utilizes the aforementioned carbon-fiber hood, with unique stainless steel twist-down hood pins. The hood serves multiple functions: aside from looking downright mean and being very light, the racy engine cover routes fresh air exclusively to the open-element filter while simultaneously channeling away underhood heat and pressure. It's a real performance piece. Furthermore, engineers have tweaked the timing curve and throttle mapping-and it shows when you plant the gas.
A New front splitter and sleek rear spoiler add downforce over the front axle to provide better overall balance. | 
Using M/T Et Street tires, we ripped to an 11.58 at 122 mph. Launch rpm was 4,200, and we powershifted the six-speed Tremec 6060 at 6,100 rpm. The 3.73 gears had us at 5,900 rpm in Fourth when we crossed the stripe. | 
Your author/driver poses with the quickest and fastest Mustang that MM&FF has ever tested on production tires. In 100 percent stock trim, the KR busted in the 11s and cracked 120 mph in the quarter-mile. |